#### Answer

3 + x

#### Work Step by Step

Commutative Property of Addition, x + 3 = ?
The question states that with using the Commutative Property of Addition, find another way to write x + 3. We know the Commutative Property states a + b = b + a which shows order does not matter.
a + b = b + a
x + 3 = ?
We define a as x and b as 3. We can then support the right side of the equation as:
x + 3 = 3 + x